How are links between periodontal and heart disease explained?

The real 'red herring' between periodontal and heart disease is the process of inflammation and the fallout that occurs from the body's inability to control it. Research has shown that periodontal (gum disease) is one of the greatest sources of chronic low-grade inflammation-sort of a silent (usually painless) alarm bell that's unanswered. The pathogenic (disease-causing) oral bacteria that's causing this inflammation in the mouth have been shown to result from imbalances in the natural ecology or 'balance of bacteria' that live in the mouth. 

As a result the gums become more permeable, allowing these bacteria to enter the bloodstream. This, in turn, has been shown to trigger the liver to make C-reactive proteins which have been shown to have inflammatory, and clot-causing, effects on blood vessels throughout the body leading to, in some studies, a tenfold increase in the chance of a heart attack or a stroke!

There are several theories about the relationship between periodontal and heart disease. Here are a few:

• Oral bacteria enter the bloodstream and attachto plaque deposits in the heart's arteries. This might lead to clots and a heart attack or stroke.
• If oral bacteria get into the bloodstream, it might cause the liver to make certain proteins that can cause inflammation of blood vessels, possibly leading to a heart attack or stroke
• Another theory is that periodontal disease makes existing heart conditions worse.

At this point, while there is an association between gum disease (or periodontal disease) and heart disease, not all of the reasons are yet known.

The American Heart Association published a Statement in April 2012 supporting an association between gum disease and heart disease. The article noted that current scientific data do not indicate if regular brushing and flossing or treatment of gum disease will decrease the incidence, rate or severity of the narrowing of the arteries (called atherosclerosis) that can lead to heart attacks and strokes. However, many studies show an as-yet-unexplained association between gum disease and several serious health conditions, including heart disease, even after adjusting for common risk factors.